1,Door controled: 4 2,Readers can connected : 4pcs 3,Number of cards: 20,000 4,Capacity of records:100,000 Nordson Professional Access Control Board: NS-M200 Two Door RS232/RS485 Network Access Control BoardFEATURES AND FUNCTIONS:1,Our Access Controller fits any type of installations, up to 20,000 users, from single buildings to multiple sites spread over remote locations and linked via RS485, ...